PendingIntent.getActivity() 处的 NullPointerException

Question

我正在开发一款具有提醒功能的应用程序。提醒保存在 sqlite 中，当使用 BootReceiver 再次创建设备重启提醒时。

部分设备出现NullPointerException。

根据 crashlytics 报告，应用程序处于后台 100%

这里是 crashlytics 日志：

Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.content.Intent.migrateExtraStreamToClipData()' on a null object reference
       at android.app.PendingIntent.getActivity(PendingIntent.java:345)
       at android.app.PendingIntent.getActivity(PendingIntent.java:308)
       at test.reminder.services.AlarmReceiver.launchAlarmLandingPage(AlarmReceiver.java:231)
       at test.reminder.services.AlarmReceiver.access[=11=]0(AlarmReceiver.java:33)
       at test.reminder.services.AlarmReceiver$ScheduleAlarm.schedule(AlarmReceiver.java:279)
       at test.reminder.services.AlarmReceiver.setReminderAlarm(AlarmReceiver.java:122)
       at test.reminder.services.AlarmReceiver.setReminderAlarms(AlarmReceiver.java:127)
       at test.reminder.services.BootReceiver.lambda$onReceive[=11=](BootReceiver.java:23)
       at test.reminder.services.-$$Lambda$BootReceiver$MU2rWs8I8r27tAltl1VUIV_8WwI.run(-.java:2)
       at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
       at java.lang.Thread.run(Thread.java:764)

相关代码如下：

public final class AlarmReceiver extends BroadcastReceiver {

    private static final String TAG = AlarmReceiver.class.getSimpleName();
    private static final String CHANNEL_ID = "alarm_channel";

    private static final String BUNDLE_EXTRA = "bundle_extra";
    private static final String ALARM_KEY = "alarm_key";

    @Override
    public void onReceive(Context context, Intent intent) {

        final Alarm alarm = intent.getBundleExtra(BUNDLE_EXTRA).getParcelable(ALARM_KEY);
        if (alarm == null) {
            Log.e(TAG, "Alarm is null", new NullPointerException());
            return;
        }

        final int id = alarm.notificationId();

        final NotificationManager manager =
                (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

        createNotificationChannel(context);

        String content = "";
        String title = "";
        if (alarm.getLabel().equals(ReminderLabelSelectionBottomSheetDialog.LABEL_BREATH_EXERCISE)) {
            content = context.getString(R.string.breath_exercise_reminder_content_message);
            title = context.getString(R.string.hello);
        } else if (alarm.getLabel().equals(ReminderLabelSelectionBottomSheetDialog.LABEL_AFFIRMATION)) {
            content = context.getString(R.string.affirmation_reminder_content_message);
            title = context.getString(R.string.hello);
        } else if (alarm.getLabel().equals(ReminderLabelSelectionBottomSheetDialog.LABEL_MEDITATION)) {
            content = context.getString(R.string.meditation_reminder_content_message);
            title = context.getString(R.string.hello);
        } else if (alarm.getLabel().equals(ReminderLabelSelectionBottomSheetDialog.LABEL_MINDFUL_PRACTICES)) {
            content = context.getString(R.string.practice_reminder_content_message);
            title = context.getString(R.string.hello);
        } else if (alarm.getLabel().equals(ReminderLabelSelectionBottomSheetDialog.LABEL_SLEEP)) {
            content = context.getString(R.string.sleep_reminder_content_message);
            title = context.getString(R.string.sleep_time);
        }

        NotificationCompat.Builder builder = new NotificationCompat.Builder(context, CHANNEL_ID);
        builder.setSmallIcon(R.drawable.ic_logo_notification);
        builder.setColor(ContextCompat.getColor(context, R.color.white));
        builder.setContentTitle(title);
        builder.setStyle(new NotificationCompat.BigTextStyle().bigText(content));
        builder.setContentText(content);
        builder.setTicker(content);
        builder.setDefaults(Notification.DEFAULT_SOUND);
        builder.setDefaults(Notification.DEFAULT_LIGHTS);
        builder.setContentIntent(launchAlarmLandingPage(context, alarm));
        builder.setAutoCancel(true);
        builder.setPriority(Notification.PRIORITY_HIGH);

        if (manager != null && alarm.isEnabled()) {
            manager.notify(id, builder.build());
        }

        //Reset Alarm manually
        setReminderAlarm(context, alarm);
    }

    //Convenience method for setting a notification
    public static void setReminderAlarm(Context context, Alarm alarm) {
        Log.d("Alarming", "set reminder");

        if (!alarm.isEnabled()) {
            Log.d("Alarming", "set reminder - alarm is not enabled");
            cancelReminderAlarm(context, alarm);
            return;
        }

        final Calendar nextAlarmTime = getTimeForNextAlarm(alarm);
        alarm.setTime(nextAlarmTime.getTimeInMillis());

        final Intent intent = new Intent(context, AlarmReceiver.class);
        final Bundle bundle = new Bundle();
        bundle.putParcelable(ALARM_KEY, alarm);
        intent.putExtra(BUNDLE_EXTRA, bundle);

        final PendingIntent pIntent = PendingIntent.getBroadcast(
                context,
                alarm.notificationId(),
                intent,
                FLAG_UPDATE_CURRENT
        );

        ScheduleAlarm.with(context).schedule(alarm, pIntent);
    }

    public static void setReminderAlarms(Context context, List<Alarm> alarms) {
        for (Alarm alarm : alarms) {
            setReminderAlarm(context, alarm);
        }
    }

    /**
     * Calculates the actual time of the next alarm/notification based on the user-set time the
     * alarm should sound each day, the days the alarm is set to run, and the current time.
     *
     * @param alarm Alarm containing the daily time the alarm is set to run and days the alarm
     *              should run
     * @return A Calendar with the actual time of the next alarm.
     */
    private static Calendar getTimeForNextAlarm(Alarm alarm) {

        final Calendar calendar = Calendar.getInstance();
        calendar.setTimeInMillis(alarm.getTime());

        final long currentTime = System.currentTimeMillis();
        final int startIndex = getStartIndexFromTime(calendar);

        int count = 0;
        boolean isAlarmSetForDay;

        final SparseBooleanArray daysArray = alarm.getDays();

        do {
            final int index = (startIndex + count) % 7;
            isAlarmSetForDay =
                    daysArray.valueAt(index) && (calendar.getTimeInMillis() > currentTime);
            if (!isAlarmSetForDay) {
                calendar.add(Calendar.DAY_OF_MONTH, 1);
                count++;
            }
        } while (!isAlarmSetForDay && count < 7);

        return calendar;

    }

    public static void cancelReminderAlarm(Context context, Alarm alarm) {
        Log.d("Alarming", "cancel reminder alarm");

        final Intent intent = new Intent(context, AlarmReceiver.class);
        final PendingIntent pIntent = PendingIntent.getBroadcast(
                context,
                alarm.notificationId(),
                intent,
                FLAG_UPDATE_CURRENT
        );

        final AlarmManager manager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
        if (manager != null) {
            manager.cancel(pIntent);
        }
    }

    private static int getStartIndexFromTime(Calendar c) {

        final int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);

        int startIndex = 0;
        switch (dayOfWeek) {
            case Calendar.MONDAY:
                startIndex = 0;
                break;
            case Calendar.TUESDAY:
                startIndex = 1;
                break;
            case Calendar.WEDNESDAY:
                startIndex = 2;
                break;
            case Calendar.THURSDAY:
                startIndex = 3;
                break;
            case Calendar.FRIDAY:
                startIndex = 4;
                break;
            case Calendar.SATURDAY:
                startIndex = 5;
                break;
            case Calendar.SUNDAY:
                startIndex = 6;
                break;
        }

        return startIndex;

    }

    private static void createNotificationChannel(Context ctx) {
        if (SDK_INT < O) return;

        final NotificationManager mgr = ctx.getSystemService(NotificationManager.class);
        if (mgr == null) return;

        final String name = ctx.getString(R.string.channel_name);
        if (mgr.getNotificationChannel(name) == null) {
            final NotificationChannel channel =
                    new NotificationChannel(CHANNEL_ID, name, IMPORTANCE_HIGH);
            mgr.createNotificationChannel(channel);
        }
    }

    private static PendingIntent launchAlarmLandingPage(Context ctx, Alarm alarm) {
        return PendingIntent.getActivity(
                ctx, alarm.notificationId(), launchIntent(ctx, alarm.getLabel()), FLAG_UPDATE_CURRENT
        );
    }

    public static Intent launchIntent(Context context, String type) {
        //Normalde labela göre farklı activityler başlatmamız gerek
        // ancak biz çoğu sayfa için fragment kullandığımız için yalnızca MainActivitye yönlendiriyoruz
        final Intent i = new Intent(context, SplashScreenActivity.class);
        i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        return i;
    }

    private static class ScheduleAlarm {

        @NonNull
        private final Context ctx;
        @NonNull
        private final AlarmManager am;

        private ScheduleAlarm(@NonNull AlarmManager am, @NonNull Context ctx) {
            this.am = am;
            this.ctx = ctx;
        }

        static ScheduleAlarm with(Context context) {
            final AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
            if (am == null) {
                throw new IllegalStateException("AlarmManager is null");
            }
            return new ScheduleAlarm(am, context);
        }

        void schedule(Alarm alarm, PendingIntent pi) {
            if (SDK_INT > LOLLIPOP) {
                am.setAlarmClock(new AlarmManager.AlarmClockInfo(alarm.getTime(), launchAlarmLandingPage(ctx, alarm)), pi);
            } else {
                am.setExact(AlarmManager.RTC_WAKEUP, alarm.getTime(), pi);
            }
        }

    }

}
public class BootReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        if (ACTION_BOOT_COMPLETED.equals(intent.getAction())) {
            Executors.newSingleThreadExecutor().execute(() -> {
                final List<Alarm> alarms = DatabaseHelper.getInstance(context).getAlarms();
                setReminderAlarms(context, alarms);
            });
        }
    }

}

这是我使用的闹钟 class：

public final class Alarm implements Parcelable {

    private Alarm(Parcel in) {
        id = in.readLong();
        time = in.readLong();
        label = in.readString();
        allDays = in.readSparseBooleanArray();
        isEnabled = in.readByte() != 0;
    }

    public static final Creator<Alarm> CREATOR = new Creator<Alarm>() {
        @Override
        public Alarm createFromParcel(Parcel in) {
            return new Alarm(in);
        }

        @Override
        public Alarm[] newArray(int size) {
            return new Alarm[size];
        }
    };

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel parcel, int i) {
        parcel.writeLong(id);
        parcel.writeLong(time);
        parcel.writeString(label);
        parcel.writeSparseBooleanArray(allDays);
        parcel.writeByte((byte) (isEnabled ? 1 : 0));
    }

    @Retention(RetentionPolicy.SOURCE)
    @IntDef({MON, TUES, WED, THURS, FRI, SAT, SUN})
    @interface Days {
    }

    public static final int MON = 1;
    public static final int TUES = 2;
    public static final int WED = 3;
    public static final int THURS = 4;
    public static final int FRI = 5;
    public static final int SAT = 6;
    public static final int SUN = 7;

    private static final long NO_ID = -1;

    private final long id;
    private long time;
    private String label;
    private SparseBooleanArray allDays;
    private boolean isEnabled;

    public Alarm() {
        this(NO_ID);
    }

    public Alarm(long id) {
        this(id, System.currentTimeMillis());
    }

    public Alarm(long id, long time, @Days int... days) {
        this(id, time, null, days);
    }

    public Alarm(long id, long time, String label, @Days int... days) {
        this.id = id;
        this.time = time;
        this.label = label;
        this.allDays = buildDaysArray(days);
    }

    public long getId() {
        return id;
    }

    public void setTime(long time) {
        this.time = time;
    }

    public long getTime() {
        return time;
    }

    public void setLabel(String label) {
        this.label = label;
    }

    public String getLabel() {
        return label;
    }

    public void setDay(@Days int day, boolean isAlarmed) {
        allDays.append(day, isAlarmed);
    }

    public SparseBooleanArray getDays() {
        return allDays;
    }

    public boolean getDay(@Days int day) {
        return allDays.get(day);
    }

    public void setIsEnabled(boolean isEnabled) {
        this.isEnabled = isEnabled;
    }

    public boolean isEnabled() {
        return isEnabled;
    }

    public int notificationId() {
        final long id = getId();
        return (int) (id ^ (id >>> 32));
    }

    @Override
    public String toString() {
        return "Alarm{" +
                "id=" + id +
                ", time=" + time +
                ", label='" + label + '\'' +
                ", allDays=" + allDays +
                ", isEnabled=" + isEnabled +
                '}';
    }

    @Override
    public int hashCode() {
        int result = 17;
        result = 31 * result + (int) (id ^ (id >>> 32));
        result = 31 * result + (int) (time ^ (time >>> 32));
        result = 31 * result + label.hashCode();
        for (int i = 0; i < allDays.size(); i++) {
            result = 31 * result + (allDays.valueAt(i) ? 1 : 0);
        }
        return result;
    }

    private static SparseBooleanArray buildDaysArray(@Days int... days) {

        final SparseBooleanArray array = buildBaseDaysArray();

        for (@Days int day : days) {
            array.append(day, true);
        }

        return array;

    }

    private static SparseBooleanArray buildBaseDaysArray() {

        final int numDays = 7;

        final SparseBooleanArray array = new SparseBooleanArray(numDays);

        array.put(MON, false);
        array.put(TUES, false);
        array.put(WED, false);
        array.put(THURS, false);
        array.put(FRI, false);
        array.put(SAT, false);
        array.put(SUN, false);

        return array;

    }

}

Answer 1

问题是AlarmReceiver.java:231:

文档中也有解释：PendingIntent.getActivity()

标志 Intent.FLAG_ACTIVITY_NEW_TASK 需要添加到 Intent:

private static PendingIntent launchAlarmLandingPage(Context context, Alarm alarm) {

    Intent intent = new Intent(context, SplashScreenActivity.class);
    // intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

    return PendingIntent.getActivity(
        context,
        alarm.notificationId(),
        intent,
        PendingIntent.FLAG_UPDATE_CURRENT
   );
}